Convective Dialysis Reduces Mortality Risk: Results From a Large Observational, Population-Based Analysis

According to many studies, extracorporeal dialysis with convective methods is associated with better clinical outcomes and a survival benefit compared to diffusive techniques. However, there is no full agreement on the actual superiority of this kind of renal replacement therapy on hard end-points such as mortality. We performed a retrospective epidemiological cohort study to provide "real-world" evidence on the impact of convective and non-convective dialysis techniques on all-cause and cardiac mortality and biochemical outcomes among dialysis patients in Sicily, the southernmost region of Italy. Data of all incident adult patients (N = 6529) who have started chronic extracorporeal dialysis over the period 2009-2015 were retrieved from the Sicilian Registry of Nephrology, Dialysis and Transplantation. There were 1558 patients receiving convective techniques (23.86%). Overall mortality rate was 45.21% with a significant difference between convective (31.39%) and non-convective (49.55%) groups (P < 0.0001). After adjustment for potential confounders in multiple Cox regression models of increasing complexity, the mortality risk remained significantly lower for patients treated with convective methods (HR, 0.581; 95%CI, 0.525 to 0.643; P < 0.0001). Moreover, the convective group had a better blood chemistry profile, improved dialysis efficacy, and reduced mortality rate from cardiac diseases compared to the non-convective group. As a sensitivity analysis, patients were categorized according to propensity score quartiles and the hazard ratio for both all-cause and cardiac mortality was significantly lower for the convective group in each quartile. In conclusion, despite the observational and retrospective design, the results of the present study further support the use of convective therapies for the treatment of end-stage renal disease.